Chain-type flails having bark-cutting bosses on the outer links thereof



y 7, 1959 R. L. DICKERSON 2,893,451

CHAIN-TYPE FLAILS HAVING BARK-CUTTING BOSSES ON THE OUTER LINKS THEREOFFiled Aug. 1, 1957 2 Sheets-Sheet I.

INVEN TOR. 2 RAYMOND L. DIOKERSON y 7, 1959 R. L. DICKERSON 2,893,451

CHAIN-TYPE FLAILS HAVING BARK-CUTTING BOSSES EREOF O N THE OUTER LINKSTH 2 Sheets-Sheet 2 Filed Aug. 1, 1957 INVENTOR. RAYMOND L DICKERSON -BYUnited States Patent 2,893,451 Patented July 7, 1959 Fire CHAIN-TYPEFLAILS HAVING BA'RK-CU'ITING BOSSES ON THE OUTER LINKS THEREOF RaymondL. Dickerson, Spokane, Wash. Application August 1, 19 57, Serial No.675,657

2 Claims. (Cl'. 144-208) This invention is a device for removing thebark from logs, and employing the principle of flailing or revolvingchain's.

Under the high competition of todays lumber market and because of thedepletion of' our natural resources reducing toa large extent the numberof top-grade trees, it is becoming more and more necessary for thesawmill operator to exercise great care in sawing logs so that he mayproduce from any given log the greatest amount of top-grade lumbercontained therein. To do so, it is necessary to cut the lumber so thatthe grain is positionedin the finished lumber in the desired manner, andalso it is desirable: to avoid as many knots as can conveniently beavoided.

Obviously to accomplish this purpose, it is desirable that one have'aclear view of the log unhindered by bark which conceals the grain. Ittherefore is becoming more and more customary to-remove the bark fromlogs prior to the sawmill operation.

Under present day practice, it is conventional to support a-log inaframeon spindles somewhat like one positions apiece ofwood for turningin a lathe, and then a debarking headis disposed to cut and scrape thebark from the log. Toa'certaindegree, this has proven satisfactory.However, it has been found that this leaves a log quite smooth andslippery and therefore makes it difiicult to' handle and: hold duringthe sawing operations, even though the grain-doesbecome visible.

In view of this I have devised the present debarking device which isspecifically designed to overcome the aforementioned undesirablefeatures, and in addition, to provide a debarking headofthe revolvingchain type which materially increases the speed at which one may removethe bark from logs and which mutilates to a slight degree the wood underthe bark so that the log is not slippery and therefore is much moreeasily handled.

I have disclosed". in the accompanying drawings one physical embodimentof my present. invention, but it is to. be;.understood that the drawingsare illustrative only and are not. presented for the purpose oflimitation, it being desired to secure the invention broadly as definedin the appended claims.

In the accompanying drawings, like numerals are, employed to'designatelike parts, and

Figure l is a view in elevation showing the debarking device on avertical plane laterally of the trackway for the log carriage;

Figure 2 is an enlarged, fragmentary, vertical cross section takenthrough the head laterally of the axis of the arbor;

Figure 3 is a still-further enlarged, fragmentary cross section taken ona vertical plane longitudinally of the axis of the arbor;

Figure 4 is a fragmentary cross section taken on the plane indicated atline 4-4 of Figure 3;

Figure 5 is a view partially in cross section and partially in elevationtaken on the planes indicated by lines 5--5 of Figure 3;

Figure 6 is a vertical cross section taken on the plane indicated byline 6-6 of Figure 3;

Figure 7 is a greatly enlarged fragmentary detail of the swivel mountfor the chains; and

Figure 8 is an enlarged fragmentary elevation of the endmost links ofone chain flail.

Referring now with a greater degree of particularity to the drawing, Ihave shown a trackwayformed by spaced parallel rails 10. A carriage 11having wheels'13' which roll upon the tracks 10 has power means (notshown) for imparting mobilizing movement to the carriage for rectilinearmovementover the trackway. There are numerous means for moving carriagesof this type, and therefore the details are omitted from the presentdrawing. The carriage supports a pair of laterally spaced longitudinallyextending shafts 14 which support two wheels 15 forming a cradle or logsupport, and it will be seen that rotation of the shafts 14 andtherefore the wheels 15 simultaneously in one direction will effectrotati'onof-the log L on the carriage. Movement of the carriage '11along the trackway 10 willeflect axial movement of the log.

Fixed adjacent to the trackway 10 is a supporting frame 16 which isstationary and which pivotally supports at 17 a vertically tiltable boom18 which is comprised of spaced channel bars 19-49 (Figure 3) which havetheir outer ends secured together by' additional channel members 20-20(Figure 2). A hydraulic cylinder 21 is mounted upon the top beam 22 ofthe support frame 16, and its piston rod 23 extends downwardly and ispivotally secured at 24 to the boom 18. A conventional valved source offluid under pressure (not shown) is communicated with the hydrauliccylinder 21 through a conduit such as 25, so that through conventionalmeans an operator may raise and lower the boom by controlling the valvewhich controls the hydraulic fluid to and from the cylinder 21.

Mounted upon the outer end of the boom in covering relation between theside bars 19 and the channel members 29 is a protective cover 26 andtherebelow midway between the channel members 20, side bars 19 carrybearings 27 on their lower flanges.

Supported in the bearings 27 is a rotatable arbor 23 which it will beseen has reduced end portions 29 disposed in the bearings and anenlarged midsection 3i At its extreme ends, the arbor has the reducedend portions 3% to accommodate the nuts and lock nuts 31 which at oneend secure a belt pulley 32 preferably of' the V- belt type andpreferably one which is adapted to engage two or more V belts B toprovide suflicient frictional drive to the arbor from the motor M.

At the opposed ends of enlarged midsection 30, the arbor 28 is alsothreaded as seen at 33-. It will also be noted that the enlargedmidsection 39 of the arbor 28 is provided with a keyway 34 in which isdisposed a conventional elongated key 35-. Carried by the arbor on theenlarged midsection 30 is a drum indicated in its entirety by thenumeral36 but which is made up of a plurality of pieces, each of whichencircles in coaxial relationship the arbor 28. As best seen in Figure 3of the drawing, the drum is comprised of a plurality of intermediatediscs 37 and alternate circumferentially reduced spacing wheels 38 keyedto the arbor by key 35. At the extreme ends, the end discs 39 areprovided with enlarged apertures 40 at their centers, and theseapertures are designed to receive a washer 41, the purpose of which willbe subsequently seen. Each of the discs 37 and 39 and the reducedspacing wheels 38 is provided with a number of apertures 42 here shownas being 4 in number, and communicating with each other, so that tiebars 43 may extend therethrough and be releasably secured by means ofthe nut and set-nut combinations 44 on the ends thereof externally ofthe end discs 39. This provides a unitary structure for the drum 36. Tohold the drum to the arbor 28, I provide nuts 45 which cooperate withthe threaded portions 33.

i In addition to the apertures 42, each of the discs in its marginaledge portions, that is, that portion extending beyond the peripheralface of the spacing wheels, is provided with a plurality of anchor rodreceiving apertures 46 circumferentially spaced equidistant and eachseries being axially aligned to receive anchor rods 47 therethrough. Inthe present drawing, the anchor rods are shown to be 12 in number.However, it will be understood that there may be more or less as founddesirable, depending upon the size of the debarking head desired.

It will be noted that the end discs 39 are each provided with an annularring 52 which covers the apertures 42 and therefore provides sockets toreceive the extreme end tors 48 which are disposed spirally about thehead 36.

That is, a swivel connector will be disposed on an anchor rod 47 betweenthe end disc and the next subsequent disc, and then the next swivelconnector will be disposed upon the next successive circumferentialanchor rod between the second and the third discs, and so on about thehead to dispose the swivel connectors 48 in a spiral arrangement aboutthe head. Each of the swivel connectors supports a chain flail 50. Inviewing the end views as seen in Figures 1 and 2, it appears that thereare 12 chain flails, but actually since there are 15 spaces formed bythe reduced spacing wheels 38, there are 15 chain fiails, some of theanchor rods 47 having two swivels 48 secured thereon but spaced 12spaces apart.

Although to some extent, bare revolving chains will remove bark from thelogs L, it is more efficient and leaves a roughened and more acceptablelog for handling when the end links of the chains 50 are provided withstriking claws or bosses as seen at 51 in Figure 8. These bosses are notseen in Figures 1 and 2, only because of the scale of the drawing, andnot because they are to be omitted from the chains. It is contemplatedthat they shall be on the end three links of each chain disposedsubstantially as shown in Figure 8, that is, with bosses midway thelength of the two links next adjacent to the end link and on the sidefaces thereof as indicated at 51a, and on both sides of the link bossesadjacent to the upper bent or annular portion as seen at 5115, andextending in the plane of the chain link. Other bosses are provided onthe lower are at 510 in the plane of the chain link and angularlydisposed with relationship to each other. While the endmost link isprovided with the bosses 51b and 51c, the bosses 51a are omitted andbosses 51d are substituted at a point adjacent to the upper arc of thelink and on opposed sides thereof, and in addition, on both sides midwaythe length of the lower are I provide bosses 51e.

As seen in Figure 1 of the drawing, the head 36 is lowered to the pointwhere the lowermost three chain links strike the bark of the log L, andthese links are the ones provided with the plural bosses. The bossespenetrate into the bark and the momentum of the chains 50 and power ofthe head 36 etfect tearing of the bark from the log L, and thus quicklyand easily remove the bark and simultaneously the bosses 51b fracturethe surface grain of the wood sufficiently to roughen it so that it isconvenient to handle the log.

It will be understood that the speed of rotation of the head is such sothat the chains do not flail the log sufiiciently hard to tear the wood,but only to remove the relatively soft bark from the harder wood. Thisspeed, of course, will vary with logs having different physicalcharacteristics.

Having thus described my invention, I claim:

1. In a log-debarking device, a revolving-chain debarking headcomprising an arbor adapted to be rotatably supported in a frame andhaving reduced end portions and an enlarged central portion; saidcentral portion being threaded on its opposed marginal end portions;said central portion having a keyway; a key in said keyway; alternatediscs and circumferentially reduced spacing wheels encircling saidcentral portion intermediate said threaded ends and being keyed to saidcentral portion by said key, the end ones of said discs each having anenlarged central aperture, washers encircling said central portion anddis' posed within the apertures of said end discs, clamping nutsassociated with the threads of said central portion and clamping saiddiscs, spacing wheels, and washers together into a unitary structure; anumber of tie bars extending through said discs and spacing wheels andsecured thereto; circumferentially spaced anchor rods extending throughthe several discs in their marginal edge portions and outwardly spacedfrom said spacing wheels; said end discs having sockets to receive theends of said anchor rods and said intermediate discs having alignedapertures through which said rods extend; swivel connectors carried bysaid anchor rods intermediate said discs and spirally arrangedcircumferentially of said drum; debarking chains carried by saidconnectors; and said chains having bark-cutting bosses on the links atthe free ends thereof.

2. In a log-debarking device of the plural beating chain type theimprovement comprising protruding bosses carried by a number of links atthe free ends of each of said chains.

References Cited in the file of this patent UNITED STATES PATENTS2,436,555 Daniell Feb. 24, 1948 2,601,261 Carpenter June 24, 19522,795,320 Dillingham June 11, 1957 FOREIGN PATENTS 135,165 Sweden Apr.8, 1952

